Re-peel adhesive tape

Abstract

The present invention provides a removable adhesive tape having excellent anchoring force between an adhesive layer and a substrate. The removable adhesive tape of the present invention comprises a substrate, a primer layer containing a binder resin and a filler, and an adhesive layer in this order. The removable adhesive tape has a protrusion in which at least a part of the filler protrudes from the primer layer to the adhesive layer, and the interface between the primer layer and the adhesive layer has a concavoconvexity.

Description

Technical Field

[0001] The present invention relates to releasable adhesive tapes. Background Art

[0002] In recent years, as wafers have become thinner, adhesive tapes have been used as supporting materials in various semiconductor manufacturing processes. In semiconductor manufacturing processes, due to the different properties required in each process, the materials used for adhesives and substrates are also diversified. As a result, it is sometimes impossible to ensure sufficient anchoring force between the substrate and the adhesive. As a method for improving the anchoring force to the substrate, a scheme of forming a primer layer on the substrate has been proposed (for example, patent documents 1 to 3). However, there is a problem that sufficient anchoring force cannot be ensured and the primer layer itself cannot be formed.

[0003] In addition, from the perspective of easy re-peeling, an adhesive tape obtained by using an active energy ray-curable adhesive is proposed. The active energy ray-curable adhesive is irradiated with active energy rays, and the double bonds of the material contained in the adhesive will shrink during curing. Among them, the adhesive using a side chain double bond-introduced polymer has a tendency to deteriorate in anchoring property to the substrate due to the curing shrinkage of the polymer itself, and sometimes residual adhesive is generated on the adherend during peeling. In particular, when the side chain of the polymer has a substituent with a long carbon chain, there is a problem of further deterioration of anchoring property.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2005-231119

[0007] Patent Document 2: Japanese Patent Application Publication No. 2009-224375

[0008] Patent Document 3: Japanese Patent Application Publication No. 2012-214585 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a removable pressure-sensitive adhesive tape having an excellent anchoring force between a pressure-sensitive adhesive layer and a substrate.

[0011] Solutions for solving problems

[0012] The removable adhesive tape of the present invention comprises a substrate, a primer layer containing a binder resin and a filler, and an adhesive layer in this order. The removable adhesive tape has a protrusion in which at least a part of the filler protrudes from the primer layer toward the adhesive layer, and the interface between the primer layer and the adhesive layer has a concavoconvex shape.

[0013] In one embodiment, the filler is at least one selected from the group consisting of silica, alumina, and calcium carbonate.

[0014] In one embodiment, the binder resin is a urethane resin.

[0015] In one embodiment, the pressure-sensitive adhesive layer includes an active energy ray-curable pressure-sensitive adhesive.

[0016] In one embodiment, the base polymer of the active energy ray-curable adhesive is an acrylic resin having a side chain double bond-introduced type.

[0017] In one embodiment, 50% or more of the side chains of the acrylic resin having a double bond introduced into the side chain are substituents having 8 or more carbon atoms.

[0018] In one embodiment, the adhesive layer further includes an isocyanate-based cross-linking agent.

[0019] In one embodiment, the height of the protrusion is 1 μm or more.

[0020] In one embodiment, the number of protrusions is 10 or more per mm.

[0021] In one embodiment, the average particle size of the filler is 0.2 μm to 2.0 μm.

[0022] In one embodiment, the adhesive layer has an anchoring force of 2 N / 50 mm or more.

[0023] In one embodiment, the substrate includes at least one resin selected from the group consisting of polyethylene terephthalate-based resins, polyethylene naphthalate-based resins, and polyolefin-based resins.

[0024] In one embodiment, the removable adhesive tape is used for semiconductor processing applications.

[0025] Effects of the Invention

[0026] According to the present invention, the excellent re-peeling adhesive tape of the anchoring force of adhesive layer and base material can be provided.The re-peeling adhesive tape of the present invention has the protrusion that at least a portion of filler protrudes from primer layer to adhesive layer, and the interface of this primer layer and this adhesive layer has concavo-convex.As a result, the contact surface area of ​​primer layer and adhesive layer becomes large, and the functional group of the adhesive included by adhesive layer and the affinity of filler can improve.And then, the reactivity with cross-linking agent at the interface of primer layer and adhesive layer can also improve.As a result, anchoring force can improve.Therefore, even when using the adhesive that comprises the double bond of side chain to import type polymer, also can prevent the residual glue for adherend. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic cross-sectional view of a removable pressure-sensitive adhesive tape according to one embodiment of the present invention.

[0028] Figure 2 This is a SEM photograph of a cross section of the removable pressure-sensitive adhesive tape according to one embodiment of the present invention. Figure 2 (a) is a photo taken at 2000 times magnification. Figure 2 (b) is a photo taken at 5000 times magnification. Figure 2 (c) is a photograph taken at a magnification of 10,000 times.

[0029] Figure 3 It is a schematic diagram explaining the method of measuring the height of the protrusion in the removable pressure-sensitive adhesive tape of the present invention.

[0030] Description of Reference Numerals

[0031] 10. Substrate

[0032] 20 Base coat

[0033] 30 Adhesive layer

[0034] 40 protrusion

[0035] 100 Re-peel Adhesive Tape DETAILED DESCRIPTION

[0036] A. Overall structure of the removable adhesive tape

[0037] Figure 1 Schematic cross-sectional view of a removable adhesive tape of one embodiment of the present invention. The removable adhesive tape 100 of the present invention sequentially comprises a substrate 10, a primer layer 20 comprising a binder resin and a filler, and an adhesive layer 30. The removable adhesive tape 100 has a protrusion 40 in which at least a part of the filler protrudes from the primer layer 20 to the adhesive layer 30 because the primer layer comprises a filler. Through the protrusion 40, the interface between the primer layer 20 and the adhesive layer 30 has a concavoconvexity. Therefore, the contact surface area between the primer layer 20 and the adhesive layer 30 becomes larger, and therefore, the reactivity at the interface between the primer layer and the adhesive layer can be improved. As a result, the anchoring force can be improved.

[0038] Figure 2 This is a SEM photograph of a cross section of a removable pressure-sensitive adhesive tape according to one embodiment of the present invention. Figure 2 (a) is a photo taken at 2000 times magnification. Figure 2 (b) is a photo taken at 5000 times magnification. Figure 2(c) is a photograph taken at a magnification of 10,000 times. In the SEM photographs taken at any magnification, the presence of protrusions formed by the filler contained in the primer layer protruding toward the adhesive layer can be confirmed. In one embodiment, a filler with a wide particle size distribution range is used as the filler. By using such a filler, it is possible to generate bumps and depressions between the fillers. Therefore, more protrusions (e.g. Figure 2 (a) and Figure 2 (b)). In addition, it was confirmed that by including a filler with a smaller particle size, fine concavities and convexities were also formed at the interface between the primer layer and the adhesive layer (for example, Figure 2 (c)).

[0039] The height of the projection is preferably more than 1 μm, more preferably more than 1.2 μm, and further preferably more than 1.5 μm. By making the height of the projection be the above range, the contact surface area of ​​the primer layer and the adhesive layer becomes larger, and the anchoring property can be improved. The height of the projection is as long as it is adapted to the thickness of the primer layer and the adhesive layer, and is adjusted to a value that can prevent the substrate from being marked when the re-peeling adhesive tape is made into a roll, for example, less than 5.0 μm. In this specification, the height of the projection refers to the distance between the flat part and the highest part of the filler presented at the interface of the primer layer and the adhesive layer. The height of the projection can be measured by any appropriate method. For example, a cross section can be made by cutting the re-peeling adhesive tape using any appropriate method, and the cross section is confirmed and measured using a scanning electron microscope.

[0040] The re-peelable adhesive tape preferably has more than 10 protrusions per mm at the cross section, more preferably more than 15 protrusions per mm, and further preferably more than 20 protrusions per mm. By making the protrusions within the above range, the anchoring property of the re-peelable adhesive tape can be improved. The more protrusions there are, the more preferred, for example, less than 150 protrusions per mm. In this specification, the number of protrusions refers to the number of protrusions per unit length of a cross section made by cutting by any appropriate method. The number of protrusions can be measured by any appropriate method. In this specification, a cross section is made by cutting the re-peelable adhesive tape by any appropriate method, and the number of protrusions within a range of 250 μm is measured at three random locations on the cross section, and the average value of the number at the three locations is converted into mm units, and the value thus obtained is referred to as the number of protrusions.

[0041] The thickness of the removable pressure-sensitive adhesive tape can be set to any appropriate value depending on the intended use, etc. The thickness of the removable pressure-sensitive adhesive tape is preferably 25 to 800 μm, more preferably 30 to 600 μm, and even more preferably 30 to 450 μm.

[0042] B. Adhesive layer

[0043] As the adhesive composition forming the adhesive layer, any appropriate adhesive may be used. The removable adhesive tape of the present invention has excellent anchoring power. Therefore, even an adhesive with high adhesive power can be suitably used.

[0044] In one embodiment, the adhesive layer includes an active energy ray-curable adhesive. The active energy ray-curable adhesive is low in elasticity and high in flexibility when pasted, has excellent handling properties, and has excellent adhesion. On the other hand, when peeling is required, the adhesive force is reduced by irradiating active energy rays, and a re-peelable adhesive tape that can be easily peeled off can be obtained. In addition, the active energy ray-curable adhesive has poor anchoring to the substrate due to the curing shrinkage of the double bonds, and the problem of residual adhesive on the adherend when peeling. The re-peelable adhesive tape of the present invention can also exert excellent anchoring power even when the adhesive layer includes an active energy ray-curable adhesive. As active energy rays, for example, gamma rays, ultraviolet rays, visible rays, infrared rays (heat rays), radio waves, α rays, β rays, electron rays, plasma streams, ionizing rays, particle lines, etc. can be listed. Preferably, ultraviolet rays.

[0045] As the active energy ray-curable adhesive, any appropriate adhesive may be used. For example, it may be an adhesive obtained by adding ultraviolet curable monomers and / or oligomers to any appropriate adhesive such as an acrylic adhesive, a rubber adhesive, a silicone acrylic adhesive, a polyvinyl ether adhesive, or an adhesive using a polymer having a carbon-carbon double bond in the side chain (hereinafter also referred to as a side chain double bond-introducing polymer) as a base polymer.

[0046] As ultraviolet curable monomers and oligomers, any appropriate monomer or oligomer can be used. As ultraviolet curable monomers, for example, urethane (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxy penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, etc. can be listed. As radiation curable oligomers, urethane oligomers, polyether oligomers, polyester oligomers, polycarbonate oligomers, polybutadiene oligomers, etc. can be listed. As oligomers, it is preferred to use oligomers with a molecular weight of about 100 to 30,000. Monomers and oligomers can be used alone or in combination of two or more.

[0047] The monomer and / or oligomer may be used in any appropriate amount depending on the type of adhesive used, for example, preferably 5 to 500 parts by weight, more preferably 40 to 150 parts by weight, based on 100 parts by weight of the base polymer constituting the adhesive.

[0048] In one embodiment, the adhesive layer preferably comprises an active energy ray-curable adhesive containing a polymer having a side chain double bond. The active energy ray-curable adhesive containing a polymer having a side chain double bond requires further anchoring properties to the substrate due to the curing shrinkage of the polymer itself. By providing the above-mentioned removable adhesive tape with a protrusion, even when using an active energy ray-curable adhesive containing a polymer having a side chain double bond, it is possible to prevent residual adhesive on the adherend.

[0049] When using an adhesive comprising a side chain double bond introduction type polymer, as a base polymer, a polymer having a polymerizable carbon-carbon double bond in the side chain and having adhesiveness can be used. As this polymer, for example, a polymer having a polymerizable carbon-carbon double bond introduced into resins such as (meth) acrylic resin, vinyl alkyl ether resin, silicone acrylic resin, polyester resin, polyamide resin, carbamate resin, styrene-diene block copolymer can be cited. It is preferred to use a (meth) acrylic resin (hereinafter also referred to as a side chain double bond introduction type acrylic resin) having a polymerizable carbon-carbon double bond introduced into (meth) acrylic resin. By using this (meth) acrylic polymer, it is easy to adjust the storage modulus and tensile modulus of the adhesive layer, in addition, it is possible to obtain an adhesive tape having an excellent balance between adhesive force and peelability. It should be noted that, "(meth) acrylic acid" refers to acrylic acid and / or methacrylic acid.

[0050] Any appropriate (meth)acrylic resin may be used as the (meth)acrylic resin, and examples of the (meth)acrylic resin include polymers obtained by polymerizing a monomer composition containing one or more esters of acrylic acid or methacrylic acid having a linear or branched alkyl group.

[0051] The linear or branched alkyl group is preferably an alkyl group having 30 or less carbon atoms, more preferably an alkyl group having 1 to 20 carbon atoms, and still more preferably an alkyl group having 4 to 18 carbon atoms. Specific examples of the alkyl group include methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, isobutyl, pentyl, isopentyl, hexyl, heptyl, cyclohexyl, 2-ethylhexyl, octyl, isooctyl, nonyl, isononyl, decyl, isodecyl, undecyl, lauryl, tridecyl, tetradecyl, stearyl, octadecyl, and dodecyl.

[0052] In one embodiment, it is preferred that more than 50 mol% of the side chain of the acrylic resin with double bond introduction in the side chain has a substituent with a carbon number of 8 or more. Acrylic resins with long-chain substituents with a carbon number of 8 or more in the side chain can prevent residual adhesive on the adherend. However, the anchoring property of acrylic resins with long-chain substituents with a carbon number of 8 or more in the side chain and the substrate may further become a problem. According to the present invention, even in the case where more than 50 mol% of the side chain is a long-chain substituent with a carbon number of 8 or more, the substrate and the adhesive layer may also have excellent anchoring property. Therefore, it is possible to take into account the anchoring property of the substrate and the adhesive layer and the prevention of residual adhesive on the adherend. More preferably, more than 60 mol% of the side chain of the acrylic resin with double bond introduction in the side chain has a substituent with a carbon number of 8 or more, and more preferably, more than 70 mol% of the side chain of the acrylic resin with double bond introduction in the side chain has a substituent with a carbon number of 8 or more.

[0053] The monomer composition forming the (meth)acrylic resin may contain any appropriate other monomers. Examples of other monomers include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride monomers such as maleic anhydride and itaconic anhydride; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxyethyl (meth)acrylate. Hydroxyl-containing monomers such as 12-hydroxylauryl ester, (4-hydroxymethylcyclohexyl) methyl acrylate, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether; sulfonic acid group-containing monomers such as styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, (meth)acrylic acid sulfopropyl ester, and (meth)acryloyloxynaphthalenesulfonic acid; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate, etc. Functional group-containing monomers. By including a monomer containing a functional group, a (meth)acrylic resin that is easy to introduce a polymerizable carbon-carbon double bond can be obtained. The content ratio of the monomer containing a functional group is preferably 4 to 30 parts by weight, and more preferably 6 to 20 parts by weight, relative to 100 parts by weight of all monomers in the monomer composition.

[0054] As other monomers, multifunctional monomers can be used.By using multifunctional monomers, the cohesive force, heat resistance, adhesion, etc. of the adhesive can be improved.In addition, because the low molecular weight components in the adhesive layer decrease, therefore, it is possible to obtain an adhesive tape that is not easy to contaminate the adherend.As multifunctional monomers, for example hexanediol (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, carbamate (meth) acrylate, etc. can be listed.The containing ratio of the multifunctional monomer is preferably 1 to 100 parts by weight relative to 100 parts by weight of all monomers of the above-mentioned monomer composition, and more preferably 5 to 50 parts by weight.

[0055] The weight average molecular weight of the (meth) acrylic resin is preferably 300,000 or more, more preferably 500,000 or more, and further preferably 800,000 to 3,000,000. If it is within this range, the seepage of low molecular weight components can be prevented, and a low-pollution adhesive tape can be obtained. The molecular weight distribution (weight average molecular weight / number average molecular weight) of the (meth) acrylic resin is preferably 1 to 20, more preferably 3 to 10. By using a (meth) acrylic resin with a narrow molecular weight distribution, the seepage of low molecular weight components can be prevented, and a low-pollution adhesive tape can be obtained. It should be noted that the weight average molecular weight and the number average molecular weight can be obtained by gel permeation chromatography (solvent: tetrahydrofuran, polystyrene conversion).

[0056] The polymer having a polymerizable carbon-carbon double bond in the side chain can be obtained by any appropriate method. For example, it can be obtained by reacting a resin obtained by any appropriate polymerization method with a compound having a polymerizable carbon-carbon double bond (e.g., condensation reaction, addition reaction). Specifically, when using a (meth) acrylic resin, a (meth) acrylic resin (copolymer) having a structural unit derived from a monomer containing any appropriate functional group is polymerized in any appropriate solvent, and then the functional group of the acrylic resin is reacted with a compound having a polymerizable carbon-carbon double bond that can react with the functional group, so that the above-mentioned polymer can be obtained. The amount of the compound having a polymerizable carbon-carbon double bond that reacts is preferably 4 to 30 parts by weight, and more preferably 4 to 20 parts by weight relative to 100 parts by weight of the above-mentioned resin. As a solvent, any appropriate solvent can be used, and various organic solvents such as ethyl acetate, methyl ethyl ketone, and toluene can be listed.

[0057] When the resin and the compound with polymerizable carbon-carbon double bond are reacted as above, the resin and the compound with polymerizable carbon-carbon double bond preferably have functional groups that can react with each other. As the combination of functional groups, for example, carboxyl / epoxy group, carboxyl / aziridine group, hydroxyl / isocyanate group etc. can be listed. Among the combinations of these functional groups, from the ease of reaction tracking, the combination of hydroxyl and isocyanate group is preferably used.

[0058] Examples of the compound having a polymerizable carbon-carbon double bond include 2-isocyanatoethyl methacrylate, methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate), and m-isopropenyl-α,α-dimethylbenzyl isocyanate.

[0059] B-1. Additives

[0060] The above-mentioned active energy ray-curable adhesive may contain any appropriate additives as required. Examples of such additives include photopolymerization initiators, crosslinking agents, catalysts (e.g., platinum catalysts), tackifiers, plasticizers, pigments, dyes, fillers, antioxidants, conductive materials, ultraviolet absorbers, light stabilizers, release regulators, softeners, surfactants, flame retardants, solvents, and the like.

[0061] In one embodiment, the active energy ray-curable adhesive preferably contains a photopolymerization initiator. As the photopolymerization initiator, any appropriate initiator can be used.

[0062] The photopolymerization initiator can be used in any appropriate amount. The content of the photopolymerization initiator is preferably 0.1 to 10 parts by weight, and more preferably 0.3 to 7 parts by weight, relative to 100 parts by weight of the ultraviolet curable adhesive. When the content of the photopolymerization initiator is less than 0.1 parts by weight, it may not be fully cured when irradiated with active energy rays. When the content of the photopolymerization initiator exceeds 10 parts by weight, it is possible that the storage stability of the adhesive is reduced, precipitation is precipitated on the surface of the adhesive layer, and outgassing is increased.

[0063] In one embodiment, the active energy ray curable adhesive further comprises a crosslinking agent. As the crosslinking agent, for example, isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, chelating agent crosslinking agents, melamine crosslinking agents, etc. can be listed. The content ratio of the crosslinking agent is preferably 0.01 to 10 parts by weight, more preferably 0.02 to 7 parts by weight, and further preferably 0.025 to 5 parts by weight relative to 100 parts by weight of the base polymer contained in the active energy ray curable adhesive. According to the content ratio of the crosslinking agent, the softness of the adhesive layer can be controlled. When the content of the crosslinking agent is less than 0.01 parts by weight, the adhesive is in a sol state and may not be able to form an adhesive layer. When the content of the crosslinking agent exceeds 10 parts by weight, it is possible that the adhesion to the adherend is reduced and the adherend cannot be fully protected.

[0064] In one embodiment, an isocyanate crosslinking agent is preferably used. An isocyanate crosslinking agent is preferred because it can react with a variety of functional groups. It is particularly preferred to use a crosslinking agent having more than 3 isocyanate groups. By using an isocyanate crosslinking agent as the crosslinking agent and setting the content of the crosslinking agent to the above range, an adhesive layer having excellent removability and significantly less residual adhesive can be formed even after heating.

[0065] The thickness of the adhesive layer can be set to any appropriate value. The thickness of the adhesive layer is preferably 4 μm to 500 μm, more preferably 5 μm to 400 μm, and further preferably 5 μm to 330 μm. By making the thickness of the adhesive layer within the above range, sufficient adhesive force can be exerted on the adherend, and the embedding property of the bumps and the sufficient embedding property of the concave and convex can be exerted.

[0066] The anchoring force of the adhesive layer (the adhesion of the adhesive layer to the substrate) is preferably 2N / 50mm or more, more preferably 3N / 50mm or more, and further preferably 5N / 50mm or more. The higher the anchoring force of the adhesive layer, the more preferred. In this specification, the anchoring force of the adhesive layer refers to: the adhesive layer is irradiated with active energy rays to cure the adhesive layer, an adhesive tape is attached to the cured adhesive layer, and the peeling force (anchoring force) when peeling is performed at a tensile speed of 300mm / minute by T-peeling. It should be noted that when using this measurement method, the anchoring force can be a low value when the content of the release agent contained in the adhesive layer is high.

[0067] C. Base coating

[0068] The primer layer includes a binder resin and a filler. By making the primer layer include a filler, at least a portion of the filler is provided with a protrusion protruding from the primer layer toward the adhesive layer. By having the protrusion, the contact surface area between the primer layer and the adhesive layer becomes larger, and as a result, the anchoring force can be improved.

[0069] C-1. Binder resin

[0070] As the binder resin, any appropriate resin can be used. For example, carbamate resins, polyester resins and acrylic resins can be listed. Preferably, carbamate resins are used. As carbamate resins, specifically, polyacrylic acid carbamate, polyester carbamate or their precursors can be listed. This is because: it is simple to coat and apply to the substrate, and a variety of substances can be selected industrially and can be obtained cheaply. The carbamate polymer is, for example, a polymer formed by a reaction mixture of an isocyanate monomer and an alcoholic hydroxyl-containing monomer (such as a hydroxyl-containing acrylic compound or a hydroxyl-containing ester compound). It should be noted that the binder resin may or may not contain a structure derived from an aromatic compound in the molecule.

[0071] C-2. Filler

[0072] As a filler, any appropriate filler can be used. For example, metal oxides such as silicon dioxide, aluminum oxide, calcium carbonate, titanium oxide, magnesium oxide and zinc oxide, talc, etc. can be listed. It is preferred to use at least one selected from the group consisting of silicon dioxide, aluminum oxide and calcium carbonate. These fillers have hydroxyl groups on the surface, so the affinity with the functional groups contained in the adhesive is higher. In addition, when using an isocyanate cross-linking agent, the reactivity with the isocyanate cross-linking agent is also good, so the anchoring force can be further improved. The filler can be used only one, or two or more can be used in combination.

[0073] The average particle size of the filler is preferably 0.2 to 2.0 μm, more preferably 0.2 to 1.5 μm, and even more preferably 0.2 to 1.2 μm. By setting the average particle size within the above range, it is possible to prevent the reverse side of the primer layer from scratching the substrate film when the removable adhesive tape is rolled up.

[0074] In one embodiment, the particle size distribution of the filler is wider and more preferred.By using a filler with a wider particle size distribution, thereby also comprising particles with substantially larger particle diameters than the average particle size, the height of the protrusion can be made into a sufficient height.In addition, by the particle size deviation of the filler each other becoming larger, even if a height difference is also produced between the fillers, as a result, the concavoconvex at the interface of the adhesive layer and the primer layer increases, and the contact surface area can be increased.As a result, anchoring can be further improved.As a method for widening the distribution of filler particle size, any appropriate method can be used.For example, a filler with a large particle size deviation can be used, or two or more fillers with different particle sizes can be mixed and used.

[0075] As the filler, for example, a filler having a particle size distribution of 0.01 μm to 10 μm can be used, preferably a filler having a particle size distribution of 0.05 μm to 7 μm, and more preferably a filler having a particle size distribution of 0.08 μm to 5 μm. The particle size distribution of the filler can be measured by any appropriate method. Examples thereof include image analysis, Coulter method, tensile sedimentation method, laser diffraction scattering method, and the like.

[0076] As filler, any filler of appropriate shape can be used. For example, spherical, flat, random shapes, etc. can be listed. From the viewpoint of improving the stability of the primer layer forming composition, spherical fillers can be suitably used. The shape of the filler can be used only one, or two or more can be used in combination.

[0077] The content of the filler is preferably 10 to 65 parts by weight, more preferably 12 to 60 parts by weight, and further preferably 15 to 60 parts by weight relative to 100 parts by weight of the binder resin. By setting the content of the filler to be within the above range, the anchoring property can be improved.

[0078] The primer layer can be formed by any appropriate method. For example, it can be formed by applying a primer layer-forming composition comprising a binder resin and a filler to a substrate. The primer layer-forming composition may further comprise any appropriate additive such as a crosslinking agent in addition to the binder resin and the filler.

[0079] The thickness of the primer layer can be set to any appropriate value. The thickness of the primer layer is preferably 1.0 μm to 4.0 μm, more preferably 1.2 μm to 3.0 μm, and further preferably 1.5 μm to 2.5 μm. In addition, the primer layer can be one layer or two or more layers. When there are two or more layers, as long as at least the layer in contact with the adhesive layer contains a binder resin and a filler, the other layers can be formed only by a binder resin.

[0080] D. Base material

[0081] The substrate can be composed of any appropriate resin. As the resin, for example, low-density polyethylene, linear polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolymer polypropylene, polybutene, polymethylpentene and other polyolefins can be listed; ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth) acrylic acid copolymer, ethylene-(meth) acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, polyurethane, polyethylene naphthalate and other polyesters; polyimide, polyether ketone, polystyrene, polyvinyl chloride, polyvinylidene chloride, fluororesin, silicone resin, cellulose resin and their crosslinked bodies, etc. It is preferred to use at least one resin selected from the group consisting of polyethylene terephthalate resin, polyethylene naphthalate resin and polyolefin resin. By using these resins, anchoring can be further improved.

[0082] The thickness of the substrate is preferably 12 μm to 210 μm, more preferably 17.5 μm to 150 μm, and even more preferably 25 μm to 100 μm. Within this range, a removable pressure-sensitive adhesive tape having appropriate rigidity, easy attachment operation, and excellent handling properties can be obtained.

[0083] The surface of the substrate may be subjected to any surface treatment in order to improve adhesion and retention with the primer layer, etc. Examples of the surface treatment include chemical treatments such as corona treatment and plasma treatment, physical treatments, and coating treatments.

[0084] E. Method for producing removable adhesive tape

[0085] The re-peeling adhesive tape can be manufactured by any appropriate method. For example, it can be obtained by the following method: the separator is coated with an adhesive solution (active energy ray curing adhesive), dried and formed on the separator. After the adhesive layer is pasted on the substrate formed with a primer layer. In addition, the above-mentioned adhesive solution is applied to the substrate formed with a primer layer, and dried, and the re-peeling adhesive tape can also be obtained. As the coating method of the adhesive solution, various methods such as rod coater coating, air knife coating, gravure coating, gravure reverse coating, reverse roller coating, lip coating, die coating, dip coating, offset printing, flexographic printing, screen printing, etc. can be adopted. As a drying method, any appropriate method can be adopted. In one embodiment, the above-mentioned adhesive layer can be formed after any appropriate curing treatment.

[0086] The primer layer can be formed by any appropriate method. For example, the primer layer can be formed by applying a composition comprising a binder resin and a filler to the substrate and drying the composition. As a coating method, the same method as that used to form the above-mentioned adhesive layer by coating can be used.

[0087] F. Application

[0088] The re-peelable adhesive tape can be used for any appropriate purpose. For example, it can be used in the processing steps of semiconductors and LEDs. In one embodiment, the re-peelable adhesive tape can be suitably used for semiconductor processing purposes. Specifically, it can be suitably used as a dicing tape, a back grinding tape, a masking tape, etc.

[0089] Example

[0090] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In the examples, "parts" and "%" are by weight unless otherwise specified.

[0091] [Production Example 1] Preparation of acrylic polymer 1 with double bond introduction in the side chain

[0092] Acrylic polymer 1 was obtained by addition-reacting 12 parts of 2-methacryloyloxyethyl isocyanate (MOI) and a copolymer obtained by polymerization using 100 parts of 2-ethylhexyl acrylate (2EHA), 15 parts of 2-hydroxyethyl acrylate (HEA) and 25 parts of acryloylmorpholine (ACMO).

[0093] [Production Example 2] Preparation of acrylic polymer 2 with side chain double bond introduction

[0094] Acrylic polymer 2 was obtained by addition-reacting 40 parts of MOI with a copolymer obtained by polymerization using 100 parts of ethyl acrylate (EA), 100 parts of butyl acrylate (BA) and 40 parts of HEA.

[0095] [Production Example 3] Preparation of acrylic polymer 3 with double bond introduction in the side chain

[0096] Acrylic polymer 3 was obtained by addition-reacting 12 parts of 2-methacryloyloxyethyl isocyanate (MOI) and a copolymer obtained by polymerizing 88.8 parts of 2-ethylhexyl acrylate (2EHA) and 11.2 parts of 2-hydroxyethyl acrylate (HEA).

[0097] [Example 1]

[0098] 100 parts by weight of acrylic polymer 1, 3 parts by weight of isocyanate crosslinking agent (manufactured by Tosoh Corporation, trade name CORONATE L), and 7 parts by weight of photopolymerization initiator (manufactured by IGM Resins BV, trade name: omnirad651) were mixed to obtain a pressure-sensitive adhesive layer-forming composition 1.

[0099] A two-component urethane ink containing no aromatic dicarboxylic acid component was gravure-printed to a thickness of 1 μm on a corona-treated substrate (polyethylene naphthalate film, thickness 25 μm, manufactured by Teijin Co., Ltd., trade name: TEONEX Q51C). Next, 60 parts by weight of aluminum oxide (manufactured by ADMATECHS, trade name: ADMAFINE AO-502, average particle size: 0.2 μm to 0.3 μm) was mixed with 100 parts by weight of a polyester urethane resin containing no aromatic dicarboxylic acid component to prepare a filler-containing primer layer-forming composition 1. The obtained filler-containing primer layer-forming composition 1 was applied to a thickness of 2 μm to form a filler-containing primer layer.

[0100] Separately, the pressure-sensitive adhesive layer-forming composition 1 was applied to a polyethylene terephthalate separator having a thickness of 38 μm to a thickness of 20 μm. Next, the pressure-sensitive adhesive layer was attached to the filler-containing primer layer and transferred to obtain a removable pressure-sensitive adhesive tape.

[0101] [Example 2]

[0102] A removable pressure-sensitive adhesive tape was obtained in the same manner as in Example 1 except that a polyolefin film having a thickness of 150 μm (manufactured by ACHILLES, trade name: POVIC) was used as the substrate.

[0103] [Example 3]

[0104] A pressure-sensitive adhesive layer-forming composition 2 was obtained in the same manner as in Example 1 except that the acrylic polymer 2 was used.

[0105] A removable adhesive tape was prepared in the same manner as in Example 1 except that the adhesive layer-forming composition 2 was used and a 100 μm-thick polyethylene terephthalate film (manufactured by Toray Industries, Ltd., trade name: Lumirror ES-10) was used as the substrate.

[0106] [Example 4]

[0107] A pressure-sensitive adhesive layer-forming composition 3 was obtained in the same manner as in Example 1 except that the acrylic polymer 3 was used.

[0108] A removable pressure-sensitive adhesive tape was obtained in the same manner as in Example 1 except that the obtained pressure-sensitive adhesive layer-forming composition 3 was used.

[0109] [Example 5]

[0110] 16 parts by weight of silica (ADMATECHS, trade name: ADMAFINE SO-C4, average particle size: 0.9 μm to 1.2 μm) was mixed with 100 parts by weight of a polyester urethane resin containing no aromatic dicarboxylic acid component to prepare a filler-containing primer layer-forming composition 2. A removable adhesive tape was obtained in the same manner as in Example 1 except that the filler-containing primer layer-forming composition 2 was used and the polyethylene terephthalate film used in Example 3 was used as a substrate.

[0111] [Example 6]

[0112] A removable adhesive tape was obtained in the same manner as in Example 1 except that the adhesive layer forming composition 3 was used and the filler-containing primer layer forming composition 2 was used.

[0113] [Example 7]

[0114] A removable adhesive tape was obtained in the same manner as in Example 1 except that the adhesive layer forming composition 2 was used, the filler-containing primer layer forming composition 2 was used, and the polyethylene naphthalate film used in Example 3 was used as the substrate.

[0115] [Example 8]

[0116] A removable adhesive tape was obtained in the same manner as in Example 1 except that the adhesive layer forming composition 2 was used, the filler-containing primer layer forming composition 2 was used, and the polyolefin film used in Example 2 was used as the substrate.

[0117] [Example 9]

[0118] 100 parts by weight of an acrylic copolymer (monomer composition ratio: 100 parts of BA, 30 parts of EA, 100 parts of acrylic acid, and 1 part of HEA) as a base polymer was mixed with 80 parts by weight of a multifunctional oligomer (urethane acrylate, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: UV-1700TL), 3 parts by weight of an isocyanate crosslinking agent (manufactured by Tosoh Corporation, trade name: CORONATE L), and 7 parts by weight of a photopolymerization initiator (manufactured by IGM Resins BV, trade name: omnirad651) to obtain an adhesive layer forming composition 4.

[0119] A removable pressure-sensitive adhesive tape was obtained in the same manner as in Example 1 except that the obtained pressure-sensitive adhesive layer-forming composition 4 was used.

[0120] [Example 10]

[0121] A removable adhesive tape was obtained in the same manner as in Example 1 except that the adhesive layer forming composition 4 was used, the polyethylene terephthalate film used in Example 3 was used as the substrate, and the primer layer forming composition 2 was used.

[0122] [Example 11]

[0123] A removable pressure-sensitive adhesive tape was obtained in the same manner as in Example 1 except that the polyolefin-based film used in Example 2 was used as the substrate.

[0124] (Comparative Example 1)

[0125] A two-component urethane ink containing no aromatic dicarboxylic acid component was gravure-printed on a substrate (polyethylene terephthalate film having a thickness of 100 μm (manufactured by Toray Industries, Ltd., trade name: Lumirror ES-10)) in a manner of 1 μm in thickness. Next, a polyester urethane resin containing no aromatic dicarboxylic acid component was applied in a manner of 2 μm in thickness to form a primer layer, and a removable adhesive tape was obtained in the same manner as in Example 1 except that the above-mentioned method was repeated.

[0126] (Comparative Example 2)

[0127] A removable pressure-sensitive adhesive tape was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive layer was transferred to the corona-treated surface of the substrate without forming a primer layer.

[0128] <Evaluation>

[0129] The following evaluations were performed using the removable pressure-sensitive adhesive tapes obtained in Examples and Comparative Examples.

[0130] 1. Height of protrusion and number of packings

[0131] For the re-peelable adhesive tape obtained in the embodiment and the comparative example, an ion milling device (made by Leica, product name: EMTIC 3X) was used to make a cross section. The produced cross section was confirmed by a scanning electron microscope (SEM) in a range of 500 to 5000 times, and the height of the protrusion and the number of protrusions (the number of units per length of the cross section of the re-peelable adhesive tape) were measured. The measurement was performed at three random locations with a length of 250 μm. The height of the protrusion was set as the distance between the flat portion of the interface between the primer layer and the adhesive layer and the highest portion of the filler. Figure 3It is a schematic diagram illustrating a method for measuring the height of a projection. It is set as the distance between the highest part of the projection 40 and the interface between the primer layer 20 and the adhesive layer 30 (two-way arrows in the example). The number of fillers is converted into the number per 1mm, and the average value of the three places is set as the number of fillers. It should be noted that for samples in which fillers fall off when making a cross section, the hollow part formed by the fall-off is measured as the height and number of the fillers.

[0132] 2. Anchoring force

[0133] The substrate used in each embodiment and comparative example was subjected to corona treatment. Next, the filler-containing primer layer-forming composition used in each embodiment was applied to the corona-treated surface of the substrate in a thickness of 3 μm to form a primer layer. Thereafter, the adhesive layer-forming composition used in each embodiment and comparative example was applied to the primer layer in a thickness of 20 μm to form an adhesive layer, thereby obtaining an evaluation sample. The evaluation sample was irradiated with 460 mJ / cm 2 The adhesive layer is cured by ultraviolet rays, and then, a cutter is used to cut the adhesive layer in a direction perpendicular to the peeling direction. Thereafter, an adhesive tape (manufactured by Nitto Denko Corporation, trade name: BT-315) is attached to the cured adhesive layer and heated at 50°C for 48 hours. Thereafter, a TENSILON tester (manufactured by A&D Corporation, product name: RTG-1210) is used to measure the peeling force (anchoring force) when peeling by T-type peeling and at a tensile speed of 300mm / min. It should be noted that although it is the peeling force (anchoring force) between the substrate and the primer layer, when the anchoring force is high, peeling occurs first between the adhesive layer and the adhesive tape. The anchoring force at this time is set to be above 8.0N / 50mm.

[0134] If the anchoring force is 3.0 N / 50 mm or more, the anchoring property is good.

[0135] [Table 1]

[0136]

[0137] Industrial Applicability

[0138] The removable pressure-sensitive adhesive tape of the present invention can be suitably used in semiconductor processing applications.

Claims

1. A removable adhesive tape comprising, in order, a substrate, a primer layer containing a binder resin and a filler, and an adhesive layer, The removable adhesive tape has a protrusion in which at least a part of the filler protrudes from the primer layer toward the adhesive layer. The interface between the primer layer and the adhesive layer has projections and depressions. The adhesive layer includes an active energy ray-curable adhesive, The base polymer of the active energy ray-curable adhesive is an acrylic resin with a side chain double bond introduction type. The removable pressure-sensitive adhesive tape has 10 or more protrusions / mm in the cross section.

2. The removable adhesive tape according to claim 1, wherein The filler is at least one selected from the group consisting of silica, alumina, and calcium carbonate.

3. The removable adhesive tape according to claim 1, wherein The binder resin is a urethane resin.

4. The removable adhesive tape according to claim 1, wherein In the acrylic resin having a double bond-introduced side chain, 50 mol % or more of the side chains are substituents having 8 or more carbon atoms.

5. The removable adhesive tape according to claim 1, wherein The adhesive layer further includes an isocyanate-based cross-linking agent.

6. The removable adhesive tape according to claim 1, wherein The height of the protrusion is 1 μm or more.

7. The removable adhesive tape according to claim 1, wherein The average particle size of the filler is 0.2 μm to 1.2 μm.

8. The removable adhesive tape according to claim 1, wherein The adhesive layer has an anchoring force of 2 N / 50 mm or more.

9. The removable adhesive tape according to claim 1, wherein The substrate includes at least one resin selected from the group consisting of polyethylene terephthalate resins, polyethylene naphthalate resins, and polyolefin resins.

10. The removable adhesive tape according to claim 1, which is used for semiconductor processing applications.

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